#include<bits/stdc++.h>
using namespace std;
#define int long long
signed main() {
	int x;
	cin >> x;
	int k = sqrt(x), flag = 0;
	for (int i = 2; i <= k; i++) {
		if (x % i == 0) {
//			cout<<i<<endl;
			flag = 1;
			break;
		}
	}
	cout << x;
	if (flag || x < 2)
		cout << " is not a prime number.";
	else
		cout << " is a prime number.";
	return 0;
}
